The 2017 ACC/AHA High Blood Pressure Guideline highlights the following key evidence gap: ?Knowledge of the effects of antihypertensive treatment for patients with dementia and patients who reside in long-term care facility settings is needed.? The proposed research will be the first large-scale study of blood pressure control among residents in long-term care with and without Alzheimer's disease and related dementias (ADRD). Long- term care residents are a highly vulnerable population, with more than 70% prevalence of ADRD or cognitive impairment, and the majority have hypertension. However, persons living in nursing homes and those with ADRD have been excluded from randomized trials evaluating the benefits and risks of lowering blood pressure. Moreover, observational studies suggest that low blood pressure may accelerate cognitive and functional decline or increase risks for adverse outcomes. Clinicians treating high blood pressure in nursing home residents must extrapolate data from trials that included younger persons or elders with better cognitive function and fewer chronic conditions. Guidelines suggest caution when initiating or intensifying antihypertensive medications or higher blood pressure goals in vulnerable elders, such as those with ADRD. However, there is no guidance on whether or when treatment should be deprescribed, defined as drug discontinuation or dosage decrease. Our goals are to (1) conduct a rigorous epidemiologic study of hypertension management among 130,000 elders with and without ADRD residing in VA nursing homes; and (2) use state-of-the-art causal inference methods to evaluate the prognosis of antihypertensive prescribing patterns in this population. Our overall hypothesis is that low blood pressure is harmful, especially in those with ADRD and on multiple antihypertensive agents. We further hypothesize that deprescribing will be associated with preservation of cognitive and functional status without increasing cardiovascular or mortality risk. The VA is the only feasible setting to conduct this study because the health care system includes nursing homes, which allow for the large-scale linkage between VA health records and Centers for Medicare & Medicaid Services (CMS) data. Prior studies limited to CMS data do not have risk factors (e.g. blood pressure), laboratory measures (e.g. kidney function), and detailed electronic health record data. We have the following aims in this study of VA nursing home residents with and without ADRD: 1) To evaluate the association of systolic and diastolic blood pressure with patient-centered and clinical outcomes; 2) To assess prevalence and intensity of antihypertensive medication use and its association with patient-centered and clinical outcome; 3) To evaluate the association of medication changes with patient-centered and clinical outcomes. This research will provide foundational evidence on the effect of low blood pressure levels and treatment among older adults with and without ADRD residing in nursing homes, with the long-term goal of informing optimal care strategies to manage hypertension in this growing and vulnerable population.